Effect of graphene nanoplatelets and microparticulated zirconium oxide on the properties of HDPE-based composite film

Abstract

This study presents the fabrication and characterization of high-density polyethylene (HDPE) composite films reinforced with either graphene nanoplatelets (GNP) or zirconium oxide (ZrO₂) via blown film extrusion with emphasis on their thermal, mechanical, structural, optical, and morphological properties. Three different concentrations of graphene (0.01, 0.10, and 0.50 wt%) and zirconium oxide (0.50, 1.00, 2.50 wt%) were evaluated. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensile and dynamic mechanical thermal (DMTA) analyses, Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), light transmission and opacity, and water vapor permeability were evaluated. For the morphological analysis of the film surface, a field emission scanning electron Microscope (FE-SEM) was used. TGA demonstrated that both fillers improved thermal stability of the composites, particularly for higher filler content. DSC revealed an increase in the crystallinity of the films, with the ZrO₂-reinforced composites reaching crystallinity levels of up to 57%, in contrast to 37% observed for neat HDPE. Tensile test showed localized improvements in strength and stiffness, with ZrO₂-reinforced composites exhibiting a higher Young’s modulus, whereas GNP-reinforced composites preserved favorable elongation at break. DMTA indicated that values of the storage and loss moduli increase with filler content. XRD and FTIR did not show changes among the samples analyzed. The opacity of the films increases with ZrO₂ while a decreasing was observed when graphene was incorporated (with exception of 0.50 wt% GNP). In general, the light transmission decreases with filler concentration and the water vapor permeability. This research demonstrates the potential use of the composites produced via blown film extrusion for different areas.